Signal / TextSecure on the other hand is encrypted by default, implements more thoroughly audited cryptography, and is recommended by Edward Snowden and Bruce Schneier.
I don't use it because it doesn't sync chats between devices or have a desktop client.
Full-on e2e is great, and I'd use Signal if it supported my use case, but it doesn't. So I use Telegram instead, as a fast, easy-to-use, grandparent-compatible chat client with sane picture and file-transfer support. The oddball encryption and the fact that it's not end-to-end by default is a downside, but it's better than plaintext and it's actually useful to me, so…
Don't get me wrong, Signal is absolutely the right choice for people who don't need or care about multi-device syncing and only need a mobile client, or people who want the best security they can get. I fully support the widespread adoption of top-tier cryptography, including by people who don't need to protect their communications from global powers. But right now Signal is not (yet?) a one-size-fits-all solution.
> The UX is nice. The crypto is like being stabbed in the eye with a fork. https://twitter.com/matthew_d_green/status/66668673163526553...
Which pieces of information do you need exactly? You can search HN for 'Telegram', it get's criticized nearly every time it makes headlines. Or just look at Telegram's interface and you'll see that 'secret chat' is not the default option, it's not end-to-end encrypted by default making it marginally more secure than HTTPS.
Signal/TextSecure on the otherhand has been the 'golden child' of the privacy and infosec scenes since it was released and their website has plenty of documentation on their protocol.